For example, a belt for a continuously variable transmission (CVT) used as a transmission of an automobile is composed of a laminated ring in which a plurality of endless stripe metal rings are laminated and assembled in their thickness direction. The laminated ring of this type is laminated by selecting metal rings of each layer manufactured individually so that its circumferential value or radius will basically be a design value (this value mutually differs for each layer) and assembling them. Subsequently, this work is repeated only for the necessary number of laminated rings.
However, a metal ring that constitutes each layer of the laminated ring is manufactured so that its circumferential value or radius will basically be a design value, but it does not always match the design value at high accuracy. In general, a certain degree of dispersion occurs around the design value due to a production error. Accordingly, when the metal ring of each layer is combined and laminated, a desired laminated ring cannot always be obtained even if the metal ring of each layer is selected and combined arbitrarily (at random) one by one.
Hereupon, to assemble the laminated ring, after the metal ring of each layer is manufactured, size data, such as circumferential values of metal rings are measured separately, and each metal ring is stored in a part housing shelf in connection with measurement data. Further, the metal ring of each layer is selected and extracted individually from the part housing shelf in accordance with combination conditions preset for selecting and combining the metal ring of each layer.
As a part housing or extracting apparatus that houses a part, such as the metal ring, in the part housing shelf or extracts the housed part, for example, the part housing or extracting apparatus described in Japanese Patent Laid-Open Publication No. 61-131845 and Japanese Patent Laid-Open Publication No. 6-321320 is known. The part housing or extracting apparatus described in each of the Japanese Patent Publications is provided with a freely rotating housing shelf having a part housing unit defined by partitioning a peripheral edge of a cylindrical body into many stages and many columns and of which the end face of the outer peripheral edge surface is opened and part conveying means secured and provided at the position fronting on the external surface of the housing shelf. Further, the part conveying means is provided with a part holding member that freely moves along the external surface of the housing shelf in the vertical direction. Accordingly, the part housing or extracting apparatus holds a part, such as the metal ring, by the part holding member and can house it in the part housing unit or can extract the part housed in the part housing unit.
However, because the part housing or extracting apparatus performs both operations of the housing or extracting of a part by fixed part conveying means, it takes time for the housing or extracting of the part and improvement is desired.